Helena Bonham Carter & Tim Burton Expecting a Baby

Helena Bonham Carter and her beau, director Tim Burton, and are expecting their second child together, her rep tells PEOPLE exclusively.

"[They] are very happy to be expecting their second child later this year," says her rep, Karon Maskill.

Their baby is due in December. The couple already have a 3-year-old son, Billy Raymond Burton.

Burton and Bonham Carter first worked together when he directed her for 2001's Planet of the Apes. The family is currently on vacation in Italy.

Bonham Carter, 41, made her name starring in such dramas as Howards End and Room with a View. She also received a Best Actress Oscar nomination for her 1998 film The Wings of the Dove. More recently, she has taken on quirky roles in Burton's films such as Big Fish and Charlie and the Chocolate Factory.

Burton, 48, is the brains behind some of Hollywood's most endearingly kooky films and has a close working relationship with Johnny Depp. Among other movies, he has helmed Ed Wood, Edward Scissorhands, Sleepy Hollow, Batman, Beetle Juice, and the upcoming Sweeny Todd, which stars both Depp and Bonham Carter.

The unconventional couple famously lived in adjoining London homes, with an interconnecting door but different decor. "Mine is Beatrix Potter and his is James Bond," she told the BBC's Radio Times in 2003. (They have since knocked down the dividing wall to make one large residence – no word on the decor though, perhaps it is Beatrix Bond.)

Burton cast a spell on Bonham Carter, whose great grandfather was liberal British prime minister Herbert Henry Asquith, after their first meeting. "I met Tim again at my brother's house, and magic happened," she told the Radio Times. "It was like someone taking my world and twisting it a crucial 15 degrees."